Summary: Groundwater contamination by chlorinated compounds is a significant risk to public health. Chlorine-containing compounds?ranging from pesticides to industrial solvents?are slow to degrade through natural pathways. Their wide-ranging presence is notable; for example, the industrial solvent trichloroethylene (TCE) has been detected at over fourteen-hundred DOD installations, twenty-three DOE installations, and thousands of commercial and residential sites nationwide, including 60% of Superfund sites. Although various remediation techniques are under study, all sites would benefit from rapid, ppb-level monitoring. These compounds are widely present at minute, low-part-per-billion (ppb) concentrations. At the same time, our water sources are threatened by numerous other pollutants with regulatory limits at ppb-levels. Currently available laboratory-based tools that can measure these very low concentrations are expensive, complex, and cumbersome instruments. They do not enable the types of rapid, frequent, economical and broad-based testing needed to adequately monitor the nation's water sources. Next-generation capabilities to test water samples at sub-ppb for a wide-variety of compounds in fewer than five minutes would vastly improve the capabilities of water monitors and researchers. This ability will in turn allow water suppliers to increase monitoring frequency and to implement remediation steps, and will allow researchers to focus on obtaining more data and a better understanding of the health effects of chronic exposure. OndaVia is developing the required advanced monitoring technology. For the multi-phase SBIR project envisioned here, OndaVia proposes to develop, prototype, validate, and commercialize a rapid-analysis instrument designed to measure compounds in aqueous solution using surface- enhanced Raman spectroscopy (SERS). This instrument relies upon OndaVia's proven and proprietary SERS detection technology that is both sensitive and quantitative, resulting in an easy-to- use, rapid-analysis instrument with few-parts-per-billion sensitivity. Specific Phase II Aims are focused on delivering a prototype TCE analysis kit capable of detecting TCE at 5-ppb in field samples. Phase II success will set the stage for follow-on ?Phase III? commercialization with our private-sector investors and industry partners.